ABCD

Example

A
C
B
_
A
B
B
19
B
C
C
25
17
_
23
 
 
A
B
C
_
_
_

Solution

A
C
B
21
A
B
B
19
B
C
C
25
17
25
23
 
 
A
B
C
5
7
9
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ABCD
ABCD

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